Hydraulic fan motor

[Iceni John]

I have to replace my hydraulic radiator fan motor  -  the present Webster YC is running far too slow, even on its fast setting, and it seems to be leaking badly internally, so I assume it's worn out.   I see Danfoss K-series fan motors on eBay for Gillig buses (Danfoss made some Webster after Sta-Rite, so they're functionally the same), but they're all 1.63 cu.in./rev.   My old Webster is 1.94 cu.in./rev, the largest size the YC was made in.   So, the big question is, will a 1.63 motor turn my fan as well as the old 1.94 motor?   I'll also be replacing the archaic old metal fan with something better such as a modern multi-blade fan to pull more air through the radiator.

Any hydraulic gurus here who'd know if this capacity difference will still work OK for me?   I had a quote of $780 for a new YC motor!   That's way too much.

Thanks, John

[luvrbus]

? is your fan tied to the DDEC by the way of a vehicle host control like the Blue Birds,the bird owners that I am around replace the Webster 1.94  with a 1.94 motor from Northern Tool for less than $200.00.I'll check with one guy for a number for you I remember it was a high torque motor so I don't think a 1.63 is going to work on a bus  

[Iceni John]

No, my fan's high/low speed controller is a simple solenoid valve thingy that restricts fluid flow to the motor until the coolant reaches 195 degrees, then a Kysor switch opens and the fan runs at full speed until coolant drops to 189 degrees.   I was reading about the Blue Bird system  -  mine's simpler than that!

My concern was that a smaller capacity motor would not have enough torque to turn a 26" fan at 2000+ RPM without overheating, especially if I change to a better fan that may need more power if it pulls more air.   There's probably a good reason Crown used the biggest and most expensive size of fan motor in the first place.   Yes, $200-ish is better than almost $800, as long as it works correctly.   Whatever motor I get has to be a SAE type A 2-bolt, but the shaft can be whatever type will fit the new fan's hub  -  my Webster now has a tapered keyway with a 3/8" nut.

I'll also be recoring my radiator because it has a cold spot in it, and make the core 2" higher to increase its area by about 7%  -  every little bit helps.   With a new core, a better fan, and a motor that turns it fast enough, I hope to solve my ever-worsening overheating once and for all, hopefully without needing misters as well.   I may also install a separate transmission fluid cooler ahead of the engine's shell cooler to reduce any transmission heat being dumped into the coolant, but that's a job for another day!   When all the coolant is drained out, I'll try to change the thermostats as well, even though I think they're working OK now, and I may also open up the water pump to check its impeller for wear.   Lots to do!

John

[Tom Y]

I am running one from a Gillig on my L10. I have a new old stock on the shelf, sorry not aval. I will look for the number on it if you wish. These are directional, I had to take it apart to run the blade I had. But not have a new blade. The smaller hyd motor will spin faster, but enough torque? My system is like yours, slowly turns the fan until temp is reached. I also put it on a switch so I can dump heat when stopping.

[Tom Y]

Here's a build pic of it.

[buswarrior]

Iceni John,

Boost the priority, if you have heat problems:

Get the transmission heat out of the engine coolant sooner than later.

One of the long gone engineers knew the heat rejection of the auto transmissions, all I can remember is that it was significant heat!

Like a third or half of the motor, or something big like that. Compare MC7 rads to MC8 rads, that was all for the auto transmission.

Hayden makes a lovely unit that will attach to, or inside, the curb side engine door. Blow your fans out, not in.

edit: on an MCI... the Crown will have other good places to stash a Hayden! Don't let it fight the engine fan, it will lose!

happy coaching!
buswarrior

[luvrbus]

You don't want to take too much heat from a Allison,180*-190* is a good number for a Allison a cold running Allison will sludge up and you will have all kinds of control valves and solenoid problems later down the road so figure away you can control the air to oil cooler temperature   

[thomasinnv]

Don't know about a bus but with cars and trucks i have had good success plumbing the trans through an external air to oil coller first, then through the water to oil cooler. That way a lot of the heat gets shed before going into the water to oil cooler, and the water to oil cooler will actually shed heat into the trans oil if the temp is lower going into the cooler. Keeps the trans from running too cool in colder climate (my truck is plumbed this way from factory). Another option would be a thermostatically controlled fan on the air to oil cooler.

[Iceni John]

Yes, the Hayden is what I'll use for the transmission, with a thermostat so the fan doesn't come on below 180 degrees.   It will then feed the engine's oil and fluid cooler in the normal way to help warm up the fluid when cold.   I can mount it in a spare space just behind the driver's side rear wheels, and it's away from the radiator's air flow there.   I don't know how much heat a 740 makes when in lockup (i.e. almost all the time), but every degree less heat being dumped into the coolant will help overall.

My thought about all the 1.63 Gillig fan motors on eBay is that they're for 4-stroke engines, but Crown chose the biggest 1.94 motor to turn the fan as fast as possible for the 6V92's greater cooling requirements.   I'm curious what size motor Gillig used for their 6V92 Phantoms?   Anyway, a 1.63 won't work right, so I have to find an affordable 1.94.   I was reading a Sauer-Danfoss technical blurb last night about hydraulic cooling systems, and they stress that no individual part should be changed from the original specifications otherwise Bad Things could happen  -  seems reasonable to me.   Parker makes their PGM 610 in a 1.95 size, and I think Eaton also makes one about that size  -  I just don't want to pay crazy Webster prices!   I also have to be sure the motor is intended for radiator fans, otherwise the axial load on the output shaft could damage the wear plate inside and cause it to leak internally.

Luvrbus, I looked on the Northern Tool website but didn't see a motor there that would work for me.   They have some $300+ motors, but I can't find out what their specs are.   I'll probably end up getting a Parker or Eaton because they're readily available and have seal kits and parts available if I need in the future.   I'm curious what the Wanderlodge folk use in their 2-stroke coaches.

Thanks everyone, John

[luvrbus]

I am always afraid to use a after market motor myself,I had to replace a $2500.00 radiator on a model 15 Eagle where the guy install a aftermarket motor because he didn't won't to pay Sunstrands prices and the aftermarket motor the shaft broke.It cost him a new 500 buck fan,shroud,motor and radiator all the parts to restore it back to original was close to 5 grand lol 800 bucks could be cheap in the long run   

[Iceni John]

I entirely agree with you about aftermarket parts of unknown provenance.   However, Parker and Eaton are both well-respected brands, and if their motors are specifically suitable for fans then shouldn't I be OK with them?   I would not use an unknown-name motor (like some available online), or something questionable.   Nothing Chinese for any critical areas.   As a general rule, everything I do to the bus is at least to Crown's original build quality or better  -  no shortcuts for me!   I sometimes imagine what Crown's engineers would say of all the work I've done so far to the bus  -  would they be impressed with it and think it worthy of Crown's name?   I hope so.   I think that Parker's gear motors are made in Germany, so they should be good.   If I can find a QCC/Danfoss/Webster YC 1.94 for less than $780 I'll get it, but they're not common motors  -  the quote I got was to have one made from parts to my specifications, so I wonder how well it would be assembled if it isn't factory-made?

Thanks, John     

[luvrbus]

A dumb ? but why not have the motor rebuilt it's probably just the vanes wore to much

[eagle19952]

A dumb ? but why not have the motor rebuilt it's probably just the vanes wore to much

these folks performed miracles for me
if nothing else i would run my needs/wants past them, i bet there are  others in the 48 states with the same talent...

http://www.alaskahydraulics.com/index.php/products

[Iceni John]

I asked QCC (the current manufacturers of the YC series of gear pumps and motors) if the motor's special rebuild kits are still available, and their answer was "probably not"!   The pumps' kits are still available, but the motors need a different high-pressure seal and a different thrust plate inside.   A local hydraulics repairman I spoke with said that the gears' bores and sleeve bushings in the housing are probably worn, in which case there's nothing to be done  -  he says that after 25 years of use it's probably time for a new motor.   Unfortunately I can't get the old motor out until the radiator is removed, and I'm still trying to find someone local who can build me the core I want, instead of selling me what they want to sell!   To minimize downtime I had planned to get the new motor and new fan before the radiator is done, then everything could be done at the same time.

These YC motors seem to be the orphan step-child of QCC.   I get the impression that they've lost interest in supporting them now.   That's another reason I'm thinking it will be better to buy another make with better parts availability and support.   If you have any recommendations for an alternative, I'm all ears!

I'll certainly look at the Alaskans' website, but I would rather deal with someone local  -  face-to-face is my preferred way of doing business like this!

Thanks, John

[eagle19952]

I'll certainly look at the Alaskans' website, but I would rather deal with someone local  -  face-to-face is my preferred way of doing business like this!

Thanks, John

everything in Alaska is imported they might know a source .. maybe not. i have not called them in years